Help Malware?

[jussiseppo53]

Hello. I downloaded a game from internet (not google play store) to my tablet (galaxy tab S) after playing a while, the tablet turned itself off without me doing anything and it said android is upgrading. then my phone started showing ads and installing apps without my permission. i deleted the game but it didnt help. there is a new app im not able to remove or disable.... it even wasnt device admin... i even tried factory reset, but it didnt do anything.
The phone is fully stock and not rooted. im not going to reinstall my rom or root the phone. i dont have pc to do it with and i might risk breaking it. How did this happen and how can i fix it?

 

[Member 1919122]

You've now learned the hard way, do not install anything from legit sources. I can't even begin to help you out.

 

[jussiseppo53]

well that sucks... do you think there is any way to fix this?

 

[svim]

im not going to reinstall my rom or root the phone. i dont have pc to do it with and i might risk breaking it. How did this happen and how can i fix it?

You might need to be a little more flexible and except that you're most likely need to reinstall with the original ROM or root. Or take it to a trusted repair shop and pay to have them restore your Tab.

 

[Jfalls63]

If you saw the message "Android is Upgrading" then something got installed into the system and the only sure way to get rid of it would be to flash the stock firmware, PC required.

 

[chanchan05]

Reflash firmware, or root an uninstall. Both times voiding your warranty.

 

[mikedt]

Sounds like the game had root exploit malware in it. You play the game, it sneakily roots your phone or tablet, installs its payload in system(Android is upgrading), and basically it's now pwned. You'll have to re-flash it using Odin, PC required.

The tablet is no longer stock and is now rooted, that's what the malware payload in the game does, and why factory reset won't clear it.